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Plastics lead a sporting life

Article-Plastics lead a sporting life

Plastics lead a sporting life

As the weather warms up, so do sales at sports and recreational equipment outlets. The ringing cash registers bring a sparkle in the eyes of plastics and composite producers that supply the materials for everything from water sports and camping equipment to golf and boating gear. And the rewards are not minuscule.

Last year and into part of this year, sports and recreational equipment accounted for some 267.9 million lbs of plastics sales, according to the Plastic Buyer Profiles complied by Phillip Townsend Associates, Inc., Houston, TX. Camping, fishing, and hunting equipment led the way with some 65.5 million lbs consumed for these activities, followed closely by pool, swimming, and diving products with 60.8 million lbs marketed.

Polyethylene heads the list when it comes to the types of resins employed in the sports and recreational arena, with 159.5 million lbs of plastics going into these products. The next closest resin was polypropylene, with sales reaching 50.3 million lbs during the 1996-1997 time period. Here's a look at some of the innovative uses for these materials.

Extreme games. If hot weather has you in the doldrums, this adventure should help cool you off. Arctic explorers Lonnie Dupre of Grand Marais, MN, and John Hoelscher of Yeppoon, Queensland, Australia, have joined forces for a 4,600-mile, 15-month expedition around Greenland. The journey began May 15th and constitutes the first ever circumnavigation of Greenland by ground transportation.

The expedition departed from Paamiut on the southwestern coast and traveled 1,420 miles north by sea kayak to Pituffil (Thula Air Field). The team will depart by dog sledge to travel the 2,560 miles of Arctic coastline and sea ice through the winter and early spring of 1998. This will put them in contact with the North Greenland Inuit, one of the Earth's most isolated people. At Ammassalik on the southeastern coast, the expedition will travel the remaining 760 miles by sea kayak back to their starting point.

What does this record-breaking expedition have to do with plastics? For one thing, THV fluoropolymer supplied by Dyneon (St. Paul, MN) will accompany the excursion. Because the material has great flexibility and optical clarity, plus processing versatility, it seemed the perfect solution for tent and kayak sail windows. Even with these properties going for it, the material does not sacrifice its weathering, chemical, hydrolysis, soil resistance, low flammability, and low water absorption qualities.

Previous attempts to circumnavigate Greenland have failed, and this geographic "first" still remains elusive. However, by incorporating contemporary modifications like THV into traditional dog sledge and kayak designs, Dupre and Hoelscher should be able to cope with any conditions they expect to encounter.

The team plans to travel 7 to 12 hrs per day, and cover an average of 22 miles. On a regular basis, the expedition will give updates and send out digital photographs from the trail using a laptop computer. The journey also opens the door to Dyneon THV applications not explored to date. These include map cases, boat covers, and fish-house accessories.

"The circumnavigation of Greenland by dog sledge and kayak epitomizes the human spirit of adventure," says Dyneon's Bryce Johnson. "It represents an incredible test of individual will in which Dyneon is pleased to participate."

Better boating. A less demanding way to cool off under the summertime sun is to take to the water. And what more relaxing way is there to do that than in a boat. Here again, plastics help make the journey less stressful, safer, and more effortless.

The marine market turned to plastic products more than 30 years ago for materials that provided superior protection from the elements at greatly reduced weights. Today's boat builders also find that the right combination of plastic-based materials can protect the environment.

For example, Sea Pro Boats, Inc. (Newberry, SC) uses patented, foam-filled fiberglass beams, or "stringers," that offer significant weight savings and durability over traditional plywood systems. An added benefit: the beams have a non-ozone-depleting foam core.

COMPSYS, Inc., (Melbourne, FL) makes the PRISMA(R) composite preform stringer and bulkhead systems. They incorporate the ZONE3(R) rigid polyurethane foam system developed by BASF Corp.'s Urethane Specialties Group (Livonia, MI).

"The PRISMA stringer system has a better load distribution when compared to plywood systems," notes Tommy Handcock, Sea Pro president. "It has reduced my stringer assembly labor costs by as much as 50%, and the stringers will not rot or decompose."

The systems are made in closed box molds. First, the mold interior is lined with stitch-bonded E-glass covered with a layer of polyester fabric. Piping and mounting hardware is then positioned inside the mold, which is then closed and injected with a predetermined amount of the ZONE3 material. Once cured, the preform is removed from the mold, inspected, and shipped to the boatbuilder, where it can be immediately wetted out and installed.

The stringer systems also can enhance the structural integrity of the boat, since they include built-in radiused edges that provide stress relief at the hull-stringer joint. In contrast, plywood stringers can create a "hard spot" where stress cracking can occur.

And from an environmental standpoint, "BASF's proprietary formulations have consistently outperformed other competing zero-ozone depleting products in terms of flow, cell uniformity, processing, batch-to-batch consistency, and quality," says Allan Syrop, technical services manager for BASF's Urethane Specialties Group.

Pollution-free boating. For more summertime enjoyment that offers a cooling environment, try a pontoon boat. Once shore-bound by restrictions prohibiting the noise and pollution of gasoline-powered watercraft on their favorite small lakes and rivers, recreational boaters are now singing "Anchors Away" aboard a new electric-powered pontoon boat.

Leisure Life Limited (Grand Rapids, MI), maker of the first thermoformed pontoon boat for this niche market, selected a weatherable polymer coextruded with acrylonitrile butadiene styrene (ABS) from Bayer Corp.'s Polymers Div. (Pittsburgh) to make the boat tough, resistant to the elements, and attractive.

"For our ElDeBo pontoon boat we needed a material that provided high rigidity, as well as high gloss and fade resistance," says Philip G. Globig, Leisure Life national sales manager. "The vast majority of our boats are made of polyethylene, but the material is not as rigid, doesn't offer the luster we wanted, and can't be glued."

Leisure Life found the solution in Bayer's Centrex(R) 825 weatherable polymer, coextruded over Lustran(R) 752 ABS resin. The combination delivers extrudability, formability, durability, and weatherability.

Primex Plastics (Richmond, IN) supplied the 891/2 x 1647/8-inch sheet. Each sheet measures 0.250-inch thick, and has a 20% layer of Centrex coextruded over 80% Lustran.

"In terms of weatherabilty, Centrex is superior to fiberglass, and it's lighter in weight," Globig explains. "It also will take a lot of punishment and still maintain like-new appearance."

The boat builder thermoforms the sheets in a three-station rotary press. Cycle times average between five and six minutes. The thermoformed sheet forms the hull and deck of the ElDeBo, and the one-piece components are joined like a clamshell. Foamed polystyrene is placed inside the hull for flotation.

"Our electric-powered pontoon boat gives a luxury boating experience back to consumers who want to socialize, fish, or swim on small lakes and rivers," Globig adds. "Centrex and Lustran resins give us a material that communicates form and beauty and delivers durability."

Sea-Doo duty. If speed is your thing, then check out the 1997 model Sea-Doo(R) XP watercraft from Bombardier Motor Corp. (Melbourne, FL). PWC Magazine called it "Best Musclecraft Value," and Personal Watercraft Illustrated touts it as the "acceleration and speed king."

The redesign includes a new hourglass hull shape, topped by a new deck and Direct Action Suspension. The combination produces solid straight-line tracking with the nimbleness and cornering that's expected from the signature watercraft that's propelled by a twin-cylinder, 110-hp Rotax(R) Marine powerplant. Once again, plastics helps make all of this happen.

For example, when Bombardier engineers began evaluating alternative materials for the Sea-Doo's storage cover, their mission was clear: find a performance thermoplastic that could reduce costs without sacrificing performance. They got that and more with HivalloyTM engineering resin alloys from Montell Polyolefins (Wilmington, DE).

By using Hivalloy W130 general-purpose resin, Bombardier's molders could process the storage covers without drying at a lower clamp tonnage, injection pressure, and temperature--all of which resulted in cost savings. What's more, scrap rates were reduced by about 25%. And since the Hivalloy resin is less dense than the PC/PBT blend used previously, resin costs dropped, as did the weight by 27%. Chemical resistance and acoustic properties also improved.

In exterior weather testing, an experimental grade of Hivalloy W resin has shown substantially better retention of original color and gloss than PC/PBT or ASA, widely regarded as the standard materials when it comes to weatherability. "The results against ASA indicate the Hivalloy W resins may be one of the most weatherable engineering thermoplastic available today," notes Ken Durgis, business director for the resins. Other applications include their use in marine deck hatches and bridge chair backs.

The benefits of plastics don't end here, however. For the XP's seat, Bombardier turned to a polypropylene thermoplastic composite from Azdel, Inc. (Shelby, NC), a joint venture between GE Plastics and PPG. The result: cost and weight reduction.

Part consolidation was the key. In the one-piece seat redesign, the composites (Azdel Plus R401-B01 40% random-glass mat and C401-B01 40% chopped fiber) replaced a rolled aluminum frame, six aluminum brackets, six fasteners, two aluminum side plates, an injection-molded seat, and a rear plastic cover.

"The design also enabled Bombardier to mold in a shock mount that formerly consisted of steel," says Matthew Marks, application development engineer at the GE Application Development Center, Southfield, MI. Adding the C401-B01 composite aided in filling out features in the shock and mount area.

Marks adds that the composite materials' strength-to-weight ratio also contributed to the seat design's ability to cut part and assembly costs, while reducing overall weight. The new seat is about 20% longer, but weighs only 10.4 lbs, the same as the old model.

A 'reel' fish story. Boats and fishing naturally go together. And to land that big one, try out Zebco's new Red Rhino reel. Adding refinement to the reel is a thumb button created by Phillips Plastics Corp. (Prescott, WI).

Zebco designers turned in a one-shot design for the thumb button to give the injection molder the overall impression of how the part should look. However, Joe Gleason, a Phillips Plastics design engineer, was given the task of creating a functional, yet aesthetically pleasing two-shot design for a button that, when depressed, would be durable enough to spring back independently. Moreover, the overmold had to cushion the thumb of the fisherman who casts numerous times for that illusive fish.

"We remodeled the geometry to remove undercuts and redesign areas that couldn't be molded," Gleason recalls. "Then we broke Zebco's one-shot design into first and second shots, created in-mold graphics, and proposed a living hinge."

Phillips Plastics engineers also recommended changes to remedy thick-to-thin wall sections that could affect aesthetics of the parts. They took venting and gating into consideration to enable the remaining thin-walled section to fill properly.

The living hinge is designed to flex when depressed, yet, due to the inherent properties of the polypropylene used, it returns to its original shape. The molded-in hinge replaces two metal components from the previous assembly. "With this design, the one-piece thumb button closes up the back of the reel and protects the gears from dust and debris," adds Zebco senior design engineer Kent Zwager.

The hinge design with tactile overmold was proven out during the prototyping phase. Here, the thumb button prototype mold was made using a stereolithography (SL) mold. SL molds are made by building mold cavities, rather than parts, in the 3-D Systems (Valencia, CA) SLA-250 machine. The molds are strengthened and placed in an injection-molding machine to produce a limited number of parts.

The two-shot design requires heat for material bonding. With SL technology, the design engineers could locate and solve potential problem areas at a cost savings for Zebco by eliminating rework on production tools. In the case of the Red Rhino reel, design verification occurred in two weeks, rather than the six weeks it would have taken using more traditional design methods. This decreased Zebco's time-to-market, giving the firm a competitive edge.

Plastics on the fly. But the tale of plastics' use to make fishing more enjoyable has yet another chapter. Take the case of a fly-fishing fin produced by Huston Plastics (McMinnville, OR).

Huston recently turned to Engage(R) polyolefin elastomers from DuPont Dow Elastomers (Wilmington, DE) to create fins that are buoyant and resist the elements. Not only did the materials meet the need, but ultimately helped Huston achieve reduced cycle time, lower barrel temperatures, reduced energy costs, and better colorability.

The fins help the fly-fisher "steer" from a float tube--an inner tube with a seat that allows access to areas tough to reach by boat. The fins originally were molded with theromplastic rubber (TPR), but the material would fall to the bottom of the water if left unattended. Also, frequent exposure to the elements and harsh chemicals often led to cracking.

"The TPR caused the fins to sink because the polymer had a specific gravity greater than 1.0," explains Bill Wylde, Houston's molding manager. "We tried everything to get them to float--we even added foam without success--which is when we decided to change the material."

The fins now float to the top because Engage has a specific gravity of 0.8. And, the material resists exposure to sun and water, as well as gasoline used in outboard motors.

"We noticed processing benefits as soon as we made the switch," Wylde adds. "We reduced overall cycle time by 15 to 20% over TPR, lowered barrel temperature by more than 37C, and cut energy expenses by using less injection pressure and speed. In addition, Engage proved easier to color since it has a clear formulation."

Moor for less. Keeping boats moored has become far more practical, thanks to over-sized, one-piece dock floats from Meese Orbitron Dunne (MOD) Co. (Ashtabula, OH). The new dock flotation system enables marina owners, operators, and designers to protect aquatic life, reduce labor costs, and increase dock life.

Rotomolded into a single, uniform piece from either linear low-density polyethylene (LLDPE) or cross-linked polyethylene (PE), the floats resist attack from water, salt, gasoline, and other corrosives. They also can withstand temperatures from -30 to 150F without distorting.

The floats come in foam-filled or hollow designs, and can stand up to severe impacts from speedboats, jet skis, and other watercraft without puncturing or absorbing water. In contrast, traditional polystyrene floats absorb water, deteriorate and contaminate the environment, while posing a danger to marine life, necessitating frequent replacement.

The foam-filled floats measure 4 x 3 x 2-ft, weigh 76 lbs, and can withstand up to 1,224 lbs of force. The same size, the hollow versions weigh 40 lbs and resist impacts of up to 1,260 lbs.

No fender benders. If you are a boat owner, you want to protect that expensive investment. One way to do that is with the "Fendergrip" that can help prevent boat damage through faster, more effective fender deployment.

The device, made by New World Marine, Inc. (Pompano Beach, FL), eliminates the time required to tie and retie lines. Its push-button feature allows boaters to set fenders instantly at just the right height to cushion bumps against the dock or other boats. A release of the button provides a positive lock to hold the fender line in place.

Fendergrip consists of four parts made of injection-molded acetal--a two-piece housing, a push-button, and a cam--plus four screws and a spring made of stainless steel. Line threaded through the unit is locked between integral teeth in the interior of the housing and the cam. Actuation of the push button disengages the cam and allows raising or lowering of the fender. Molded-in ridges on the casing and push button allow a sure grip, even for wet hands.

The housing parts consist of a special white UV-stabilized Delrin 527 acetal supplied by DuPont Engineering Polymers (Wilmington, DE). The push button and cam are molded from black, 25% glass-reinforced Delrin 577. The reinforcement provides added strength to withstand actuation and locking forces.

New World Marine specified the acetal because of its strength, toughness, low wear and friction, and its resistance to attack by salty air and water, common marine chemicals, and sunlight. "In the development stage," says company President Peter Cook, "our molder tried a competitive material, but had shrinkage problems and couldn't get the material to release from the mold."

Just how confident is Cook in his product? The Fendergrip comes with a three-year warranty that isn't common in the marine industry, but "the performance of Delrin lets us provide that service to our customers," Cook reveals. He sees broad potential for the device in other line-adjustment applications such as aviation tie-downs, tenting, and tarpaulin tensioning.

Goof-proof golf. The golfer's elusive search for the perfect drive may be over, thanks in part to a golf balled currently in testing at Spalding Sports Worldwide (Chicopee, MA).

"A few years ago Spalding began searching for a material with good low-temperature toughness and improved hardness that also had the flow needed for processing," explains Michelle Bellinger, senior polymer scientist at Spalding. The firm's search ended at AlliedSignal Plastics (Morristown, NJ) with a new material that could be blended with an ionomer and deliver the performance and durability that golfers desire.

"When we think nylon, we see AlliedSignal Plastics as a technological leader," adds Michael Sullivan, Spalding VP of research & engineering. The cover of Spalding's test golf ball consists of Capron(R) HPN TM nylon--part of the Ultra-toughTM family of nylon resins--blended with an ionomer. The cores are made of rubber; the ball is coated with urethane for shine.

The new, harder material means greater distance off the drives and better control. "These balls are very durable and long," says Bellinger. "The Capron nylon toughens the ball and will benefit the golfer who wants a low spin rate and longer distance."

"Durability is a given to a golfer. Our customers expect it. If you don't offer durability, nothing else matters," Sullivan adds. Judges for AlliedSignal Plastics' first design contest were equally impressed by naming the ball an award winner. Contest results were announced in June at the National Plastics Exposition in Chicago.

A shift in shafts. A new golf shaft--said to be the only commercially available shaft made of thermoplastic composite--also enhances a golfer's performance and comfort. The Thermo-PlasticTM shaft, designed by Quadrax Corp. (Portsmouth, RI), is said to give the golfer longer shots and better accuracy on the fairway.

Shaft construction starts with Quadrax's Unidirectional Tape, fabricated by imbedding fibers of carbon as a high-strength reinforcing material in a matrix of either nylon 6 or polyphenylene sulfide (PPS) thermoplastic resin. A 65% carbon to 35% resin ratio is used.

Multiple layers of tape are assembled into a lay-up of the number of plies and angles or orientation of fibers specified to achieve desired strength, stiffness, flexibility, and other engineering characteristics. The layers are then fused into a laminate. The design provides the shaft with the feel, playability, accuracy, and distance golfers demand.

Very high vibration damping of the nylon-based shaft gives it an even softer feel than shafts made of conventional graphite. Senior golfers especially like this feature. In contrast, the PPS-based shaft has a very crisp feel, giving a better tactile response to the fingers and hands of the golfer who hits an off-center shot. It appeals to low handicap golfers.

High vibration damping also provides a more consistent dispersion pattern of balls hit, meaning more accurate shots. Reducing the oscillation in the head--the flexing and twisting as it comes down into the ball--keeps the head square when it hits the ball to provide a straighter shot.

In several tests, Thermo-Plastic shafts performed head-to-head against conventional graphite shafts that were identical except for the material. In robot testing, balls hit by the Thermo-Plastic shaft matched the graphite shaft in distance, while providing a tighter dispersion pattern.

In tests by players, golfers drove balls on a simulated fairway defined by cones placed 40 years apart. Over 70% of the players said they preferred the feel of the Thermo-Plastic shaft to that of the graphite shaft. Balls hit with the two clubs traveled equally far in the air, but 61% of the balls hit with the Thermo-Plastic shaft landed in the target area vs. 48% by the graphite shaft.

What's next? Quadrax is working toward an ultra-light (below 60 gram) shaft, as well as different resin/fiber concentrations and sizes and shapes of shafts to further improve their feel and performance.

Cleftless cleats. But such equipment might not help if, after a day of heavy use, the golf course turns into a putter's nightmare because of the imprints left from metal spikes. With this in mind, more and more golf courses are requiring golfers to use spikes made of plastic.

Consider this. The average golf shoe features 12 metal spikes, and the United States Golf Association has computed that a player averages 28 paces per green. Multiply those 28 paces by 24 spikes: nearly 700 impressions per green times 18 greens equals 12,000 impressions per round. And with an average of 200 rounds per day, that's 2.4 million spike marks daily.

To overcome this problem, many courses offer rental shoes with plastic spikes at a reduced price or will make a metal to non-metal exchange for a slight fee. A set of plastic replacement spikes runs anywhere from $4 to $6.

One resin producer who has profited from this change is Dow Plastics (Midland, MI). Many of the spikes now on the market consist of special grades of Dow's Pellethane(R) thermoplastic polyurethane elastomers (TPUs). For instance, Pellethane 2102-90AR has "superior abrasion resistance and wear characteristics for shoe soles and cleats," says Mark A. Remmert, Dow Plastics senior product market manager. In sports and recreation applications alone, Remmert believes that some 100 million lbs of elastomers are used.

One company that has benefited from the switch from metal to plastic cleats is Softspikes(R), Inc. (Rockville, MD), who claims to be the original developer of the only patented non-metal spike. The company has cornered the market on the Senior Tour with nearly 70% usage.

"It's a change in mentality," says Kelly Elbin, vice president of marketing for Softspikes. He reports that currently four million golfers are wearing some form of an alternative plastic golf cleat. "We are truly witnessing a revolution in the game of golf," he enthuses.

Ray Floyd had this to say after a round of golf at a Massachusetts course last year: "Golf is my life, and I wouldn't be using Softspikes if it jeopardized my playing ability."

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